INTERPRETATIONS OF RULE 42, PROPULSION INTERPRETATIONS OF TERMS USED A term used as stated below is shown in italic type. Other terms that are specific to rule 42 are defined in the rule. Background rolling is the minimum degree of rolling caused by the waves. Body pumping is the movement of a sail caused by in and out or up and down body movement. A flick is the effect caused by body movement or pulling in or releasing a sail that is so abrupt that the normal shape of the sail is changed and almost immediately returned to the original shape. A pump is a single pull on a sail that is unrelated to wind or waves. Repeated means more than once in the same area on a leg. A roll is a single-cycle athwartship movement of the boat during which the mast goes to leeward and back to windward, or vice versa. Torquing is repeated fore and aft or rotating movement of the body. Yellow light area is a phrase used when it is not clear that an action is prohibited. It is unlikely that a boat in the yellow light area would be penalized, but it is possible. If the action is repeated, the likelihood of a penalty will rapidly increase. 42. Basic Rule Except when permitted in rule 42.3 or 45, a boat shall compete by using only the wind and water to increase, maintain or decrease her speed. Her crew may adjust the trim of sails and hull, and perform other acts of seamanship, but shall not otherwise move their bodies to propel the boat. INTERPRETATIONS (Basic) BASIC An action that is not listed in rule 42.2 may be prohibited under rule 42.. BASIC 2 A kinetic technique not listed in rule 42.2 that propels the boat, and is not one of the permitted actions covered in rule 42., is prohibited. BASIC 3 An action prohibited in rule 42.2 cannot be considered as permitted under rule 42.. BASIC 4 Except when permitted under rule 42.3, any single action of the body that propels the boat (in any direction) with the effect of one stroke of a paddle is prohibited.
INTERPRETATION BASIC 5 An action listed in rule 42.2 is always prohibited, even if it fails to propel the boat. (a) pumping: repeated fanning of any sail either by pulling in and releasing the sail or by vertical or athwartships body movement; INTERPRETATIONS (Pumping) PUMP Fanning is moving a sail in and out not in response to wind shifts, gusts or waves. PUMP 2 Pulling in and releasing a sail in response to wind shifts, gusts or waves is permitted, even if repeated (see rule 42.). PUMP 3 Except when permitted under rule 42.3(c), one pump may be prohibited under rule 42.. PUMP 4 A flick of a sail resulting from the sudden stopping of an eased sheet is permitted. PUMP 5 One flick of a sail due to body pumping, or a pump not permitted by rule 42.3(c), is in the yellow light area. Body movement that does not result in a flick of a sail does not break rule 42.2(a), but may break other parts of rule 42. PUMP 6 Repeated flicks of a sail due to body pumping are prohibited. (b) rocking: repeated rolling of the boat, induced by () body movement, (2) repeated adjustment of the sails or centreboard, or (3) steering; INTERPRETATIONS (Rocking) ROCK A roll of the boat caused by a gust or a lull followed by corrective body movement to restore proper trim is permitted by rule 42.. ROCK 2 One roll that does not have the effect of a stroke of a paddle is permitted. ROCK 3 Background rolling is permitted. A boat is not required to stop this type of rolling. ROCK 4 Adopting any static crew position or any static setting of the sails or centreboard, even when stability is reduced, is permitted by rule 42. and is not prohibited by rule 42.2(b).
ROCK 5 A single body movement that is immediately followed by repeated rolling of the boat is prohibited. (c) ooching: sudden forward body movement, stopped abruptly; INTERPRETATIONS (Ooching) OOCH Torquing to change the fore and aft trim of the boat in phase with the waves is permitted, provided it does not result in pumping the sails. OOCH 2 Torquing on flat water is prohibited. (d) sculling: repeated movement of the helm that is either forceful or that propels the boat forward or prevents her from moving astern; INTERPRETATIONS (Sculling) See interpretations of rule 42.3(d). (e) repeated tacks or gybes unrelated to changes in the wind or to tactical considerations. INTERPRETATION (Tacking and Gybing) TACK In a steady wind and in the absence of tactical considerations, a boat that tacks or gybes more than twice in quick succession breaks rule 42.2(e). In light wind a boat is in the yellow light area if she tacks or gybes noticeably more frequently than nearby boats. (a) A boat may be rolled to facilitate steering. INTERPRETATIONS (Rolling to Facilitate Steering) ROCK 6 Heeling to windward to facilitate bearing away and heeling to leeward to facilitate heading up are permitted. ROCK 7 Repeated rolling not linked to wave patterns is rocking prohibited by rule 42.2(b), even if the boat changes course with each roll. (b) A boat's crew may move their bodies to exaggerate the rolling that facilitates steering the boat through a tack or a gybe, provided that, just after the tack or
gybe is completed, the boat s speed is not greater than it would have been in the absence of the tack or gybe. INTERPRETATIONS (Rolling while Tacking or Gybing) ROCK 8 Body movements that exaggerate rolling and cause a boat to sail out of a tack or a gybe at the same speed as she had just before the manoeuvre are permitted. ROCK 9 It is permitted to move the mast to windward of vertical at the completion of a tack or a gybe. BASIC 6 After a tack when a boat is on her new close-hauled course, movement propelling the boat like a stroke of a paddle is prohibited under rule 42.. BASIC 7 When the speed of a boat clearly drops after she accelerates out of a tack or a gybe, and there is no obvious change of wind speed or direction, the exception in rule 42.3(b) does not apply and the boat breaks rule 42. (c) Except on a beat to windward, when surfing (rapidly accelerating down the leeward side of a wave) or planing is possible, the boat's crew may pull the sheet and the guy controlling any sail in order to initiate surfing or planing, but only once for each wave or gust of wind. INTERPRETATIONS (Surfing and Planing) PUMP 7 A pull of the sheet and guy made to attempt to surf or plane when surfing or planing conditions are marginal is permitted even if the attempt is not successful. PUMP 8 If a boat repeats an unsuccessful attempt to plane or surf, she is in the yellow light area. PUMP 9 Each sail may be pulled at a different time, but only as permitted by rule 42.3(c). PUMP 0 It is only necessary for surfing or planing conditions to exist at the position of a boat for her to be permitted to make one pull of the sheet or guy. PUMP Surfing or planing may be possible for some boats but not for others. This can be caused, for example, by local gusts or by waves from a motorboat. Also, lighter crews may be able surf or plane when heavier crews cannot. (d) When a boat is above a close-hauled course and either stationary or moving slowly, she may scull to turn to a close-hauled course. INTERPRETATIONS (Sculling to Turn the Boat) SCULL Provided the boat s course is above close-hauled and she clearly changes direction towards a close-hauled course, repeated forceful movements of the helm are permitted, even if the boat gains speed. She may turn to a close-hauled course on either tack.
SCULL 2 SCULL 3 After a boat has sculled in one direction, further connected sculling to offset the first sculling action is prohibited. Sculling to offset steering of the boat caused by backing a sail is prohibited. (e) A boat may reduce speed by repeatedly moving her helm. (f) Any means of propulsion may be used to help a person or another vessel in danger. (g) To get clear after grounding or colliding with another boat or object, a boat may use force applied by the crew of either boat and any equipment other than a propulsion engine. (h) Sailing instructions may, in stated circumstances, permit propulsion using an engine or any other method, provided the boat does not gain a significant advantage in the race.